It does not seem to be any of these: a canine, feline, porcine, bovine, equine or ursine skull. So that, if I got it right, excludes many of the more common animals.

To be honest, I am not quite sure whether that is even a carnivore or a herbivore skull :)

The canine teeth are either missing or are oddly placed in the front (normally the place of incicors) and the skull seems to have more molars than exclusive carnivores like cats. The eyes are oddly on the top of the head, not facing front like most carnivores have. So I'd go for a herbivore, or an omnivore maybe. Although the incisors (and the size of the skull) seem to count rodents out as well. But these are just guesses at this point. I'll do some more thinking and return to the topic.

Meanwhile, if you can, please attach an additional image or two from different angles.

Also, some kind of size scale woul be great. Although I can see the shades in the background, the actual size is bit hard to tell. It looks like a fairly large skull, but I might get it wrong.